The failure of Robertson’s opening monologue to live up to Rent-boy’s iconic Trainspotting monologue is indicative of the film’s major flaw. Filth is imitating a movie that’s already been imitated to death, and telling a story that’s been told to death, without having anything new to add to the conversation. It’s telling that the film’s most memorable image, the grotesque visual pun of a hallucinating Robertson looking back at his reflection to see a humanoid pig, is lifted straight from the original paperback cover of Welsh’s novel.

As one might expect, Baird’s film never escapes the long shadow cast by Boyle’s showy masterpiece (which also had the advantage of being based on a better Welsh novel), which helped define British cinema during the 1990s. But Filth also practically disappears in the collective shadows of numerous other influential films it apes as well. Trainspotting is tossed in the blender with Guy Ritchie’s gangster movies, informing not just the pitch-black humour but the gritty yet over-saturated stylistic template for the film, full of fourth-wall-breaking and hyperactive rhythms aided with slow motion and fast editing. The straight-to-camera monologues, unreliable narration and drug-addled psychotic downward spiral of its protagonist also consciously recalls territory well-trod by two other classics from the tail-end of the 90s (also adaptations of two seminal novels, by Chuck Palahniuk and Brett Easton Ellis), Fight Club (1999) and American Psycho (2000). In the meanwhile, Robertson’s bad-cop status and the film’s focus on a brutal urban crime turn it into something of a Scottish riff on Bad Lieutenant (more the Herzog than the Ferrara, since it aims for hallucinatory dark humour rather than operatic morality play).

Filth fails to live up to its many inspirations because its levels are all off. The visuals, a colourful sensory assault, feel played out and unoriginal. The humour and satire are too obvious to have any real teeth, and are dated to boot, mining cringe-worthy jokes from the very bigotry it means to criticize. Case in point: a sub-plot about one of Robertson’s colleagues being gay, and the apparent hilarity of his discomfort when Robertson drags this into the public scrutiny of their obscenely hetero-normative male colleagues. Then there’s the allegedly comical portrayal of gold-digging trophy wife Bunty (Shirley Henderson) who just wants her meek husband Bladesey (Eddie Marsan)–Robertson’s only hapless ‘friend’–to be more manly and forceful, and is shown her own desires by the aggressive attentions of the Detective Sergeant. Or the film’s ogling at cross-dressing as a symptom of mental illness, a trans-phobic holdover from the novel that’s actually toned down on-screen due to a major plot change.